In Spain parents frighten children into obedience by invoking El Coco, El Ogre or the Hombre del Saco (sack man) – all variations on the bogeyman theme. When the Spanish want to terrify foreigners, they send Barcelona.

After Spurs had fought their way past Milan in the Champions League on Wednesday Harry Redknapp, their manager, spoke of Barcelona less as potential quarter-final opponents than as outriders of the apocalypse. "Arsenal are a great team who pass teams to death in our league but they looked out of their depth [at the Camp Nou on Tuesday]," Redknapp said. "Barça were on another level. They are the team you don't want to play at the moment."

Fatalism has become a clever Redknapp trick. The previous method of lowering expectations was to say providence had landed Spurs with a surfeit of attack-minded cavaliers who lacked even a GCSE in defending. "We just don't have enough of those players," Redknapp would say, half apologising and half advertising the creative merits of his team. It worked a treat until Spurs showed their other side against Milan. Tottenham can defend; they just chose not to, until the mathematics of a 1-0 first-leg lead (and the Rossoneri's impassioned start) forced them to find another way to operate. To some critics, Arsenal betrayed their heritage by trying to contain Barcelona, away from home, while Spurs were heroic defenders of the citadel in losing the possession ratios 58% to 42% on their own soil against Milan.

These statistics are assuming a life of their own. Shots on goal have become another cudgel, freely used. Spurs managed one against Milan. Who cares now? Is anyone calling them cowards for not attacking more? Arsenal, on the other hand, have taken a fearful pummelling for not taking Barcelona on, even on the counterattack, where Theo Walcott's absence largely robbed them of the option to repeat the tactic used so successfully in the first leg.

Arsenal were exposed to vilification because they have always endeavoured to play the Barcelona way, or a version of it. Their supposed crime was to deviate from their artistic manifesto, which outsiders are always telling them they should. At the three-quarter mark in the tie, they still led, 2-1, from the first leg. Then Lionel Messi opened his magic box. On 53 minutes Arsenal equalised and were again on course for the quarter-finals. Then came Robin van Persie's dismissal and two Barcelona goals in 21 minutes against 10 men. The passing stats are embarrassing for Arsenal. But this was a tight, tense contest which Barcelona had to fight to win. It was not a massacre.

But its legacy is felt across north London. "Nobody wants Barça," declared Tottenham's William Gallas, who offers an insight into his team's inconsistency. Gallas says: "Before the match starts, in your head you tell yourself they are better. When you play a team like Blackpool or Wolves, you think you are better, and unfortunately you pay. It's a lack of experience."

This explains Tottenham's undulating Premier League form quite neatly, and demands a cure. Another psychological hang-up is the mounting fear of Barcelona, whose growing army of disciples are increasingly intolerant of the idea that there are lots of ways to play good football, beyond tiki-taka. Clearly Spain's champions are the best, and if you could watch one team before stepping in front of a firing squad it would be this majestic ensemble.

Now the rest of Europe must find a way to stop the pretty monster. Arsenal – failed. Spurs – daunted, and praying they draw someone else. Internazionale, less than 12 months ago – tick. José Mourinho's semi-final victory over Barça in last year's tournament was a triumph of nullification, if that is not an oxymoron. Chelsea, too, have blocked the sun in Catalonia. Barcelona, in theory, can be beaten – just not by superior passing, because such a thing does not exist. For the sake of dreams, we might imagine Gareth Bale tooling past an advanced Barça right-back and firing the goal that settles a close encounter.

As Pep Guardiola's men are so obviously the bogeymen, there is time for the others to devise fresh schemes and snares. Manchester United, Bayern Munich, Real Madrid, Chelsea and Inter are all still in the chase, as well as the upwardly mobile Spurs, Schalke and Shakhtar Donetsk. As Einstein passed away long ago, you would not bet on their chances of finding a formula to stop a side capable of racking up 724 successful passes against opponents as good as Arsenal, but defeatism is uncommon among the elite, and especially in the houses of Sir Alex Ferguson and Mourinho. Spurs knocking out Barcelona would leave Redknapp needing another expectation dampener. In his profession, of course, the Hombre del Saco is usually the chairman.